Add 72/21 and 30/40
1st number: 3 9/21, 2nd number: 30/40
72/21 + 30/40 is 117/28.
Steps for adding fractions
- Find the least common denominator or LCM of the two denominators:
LCM of 21 and 40 is 840
Next, find the equivalent fraction of both fractional numbers with denominator 840 - For the 1st fraction, since 21 × 40 = 840,
72/21 = 72 × 40/21 × 40 = 2880/840 - Likewise, for the 2nd fraction, since 40 × 21 = 840,
30/40 = 30 × 21/40 × 21 = 630/840 - Add the two like fractions:
2880/840 + 630/840 = 2880 + 630/840 = 3510/840 - 3510/840 simplified gives 117/28
- So, 72/21 + 30/40 = 117/28
In mixed form: 45/28
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